USE OF X-RAY IN THE HEALTH PROFESSIONS RHB 4.2 General ... · 4.2.2.8 Dentists and their...

PART IV

USE OF X-RAY IN THE HEALTH PROFESSIONS

RHB 4.1 Scope. This part establishes requirements for which a registrant is responsible, for use of x-ray

equipment by or under the supervision of an individual authorized by and licensed in accordance with State

statutes to engage in the healing arts or veterinary medicine.

RHB 4.2 General Safety Provisions.

4.2.1 An x-ray system which does not meet the provisions of these regulations shall not be operated for

diagnostic or therapeutic purposes if so directed by the Department.

4.2.2 The registrant shall assure that all X-ray machines under his control are operated only by a

radiologic technologist possessing a current, valid certificate from the South Carolina Radiation Quality

Standards Association, or a licensed practitioner. For the purpose of this Part, a radiologic technologist is

defined as a person who is a limited practice radiographer, radiographer, podiatric limited practice

radiographer or limited chest radiographer certified by the American Registry of Radiologic Technologists

or who is certified by the South Carolina Radiation Quality Standards Association or who has obtained a

certificate acceptable to the South Carolina Radiation Quality Standards Association. A person who applies

ionizing radiation to humans or performs x-ray exam setups, including, but not limited to, patient

positioning and technique selection shall be considered a radiologic technologist.

4.2.2.1 No person other than a licensed practitioner or a radiologic technologist possessing a current,

valid certificate from the South Carolina Radiation Quality Standards Association shall use equipment

emitting ionizing radiation on humans for diagnostic purposes.

4.2.2.2 No person shall employ or designate as a radiologic technologist a person who does not hold a

current, valid certificate issued by the South Carolina Radiation Quality Standards Association.

4.2.2.3 No person holding a certificate issued by the South Carolina Radiation Quality Standards

Association shall use equipment emitting ionizing radiation on humans for diagnostic purposes unless under

the direction and supervision of a licensed practitioner and unless so directed by prescription of a licensed

practitioner.

4.2.2.4 No person who is not certified by the South Carolina Radiation Quality Standards Association

shall take, use, or exhibit the title of "limited practice radiographer", "podiatric limited practice

radiographer", "limited chest radiographer", or "radiographer" or any other title, sign, display, or declaration

that tends to lead the public to believe that the person is authorized to apply ionizing radiation on humans

for diagnostic purposes.

4.2.2.5 A student enrolled in and attending a school or college of medicine, osteopathy, chiropractic,

podiatry, radiologic technology, or a curriculum approved by the South Carolina Radiation Quality

Standards Association, or a resident in an approved graduate education program of medicine, osteopathy,

chiropractic, or podiatry may apply ionizing radiation to humans without a certificate from the South

Carolina Radiation Quality Standards Association, as long as the student or resident is under the supervision

of a licensed practitioner or direct supervision of a certified radiologic technologist appropriately trained to

supervise the specific procedure.

4.2.2.6 The registrant shall display each operator's current South Carolina Radiation Quality Standards

Association certificate or the registrant may post a notice to the public that these certificates are available

for review upon request. The certificate or posting shall be displayed in public view, not obstructed by any

barrier, equipment, or other object.

4.2.2.7 The registrant shall ensure that each operator has received facility specific training to include

the equipment and operating conditions. Documentation of this training for each operator shall be made

available for Departmental review.

4.2.2.8 Dentists and their auxiliaries who meet the requirements of the South Carolina Dental Practice

Act are exempt from the requirements of 4.2.2.1 through 4.2.2.6.

4.2.3 The operator shall be able to demonstrate familiarity and competence with the facility’s operating

conditions.

4.2.4 X-ray producing machines and associated equipment shall be maintained in such a condition to

ensure that the patient and staff are not exposed to radiation unnecessarily.

4.2.5 If an x-ray system is identified as not being in compliance with the provisions of these regulations

and cannot meet the regulations, or if the registrant is unwilling to make corrections, and if that system is

accessible for use, it shall be rendered inoperable (i.e. dismantle the x-ray source from the source support

assembly) if so ordered by the Department.

4.2.6 For general radiographic systems not equipped with an operational anatomic programming

option, protocols shall be documented and readily available to the operator. At a minimum, these protocols

shall include:

4.2.6.1 Patient's body part and anatomical size, or body part thickness or age (for pediatrics), versus

technique factors to be used;

4.2.6.2 Source to image receptor distance (SID) to be used (except for dental intra-oral radiography)

and

4.2.6.3 If an AEC system is operated in a manual mode, the technique chart shall specify the

requirements of RHB 4.2.6.1 and RHB 4.2.6.2.

4.2.6.4 The technique chart shall accurately reflect techniques currently in use at the facility.

4.2.7 A sign shall be posted so as to be easily seen by the patient to the effect that if there is a pregnancy

or the possibility of a pregnancy, the physician shall be notified.

4.2.8 The effectiveness of protective equipment and apparel shall not be impaired. Lead aprons and

gloves shall be checked at least annually for cracks and holes that could compromise the radiation protection

it provides. This testing shall be documented. Records of this testing shall be kept two years, or until the

next Department inspection, whichever is later.

4.2.9 Except for patients who cannot be moved out of the room, only the staff and ancillary personnel

required for the medical procedure or training shall be in the room during the radiographic exposure other

than the patient being examined.

4.2.9.1 All individuals shall be positioned such that no part of the body will be struck by the useful

beam, unless protected by not less than 0.5 mm lead equivalent material.

4.2.9.2 The x-ray operator, other staff, and ancillary persons shall be protected from the direct scatter

radiation by protective aprons or whole body protective barriers of not less than 0.25 mm lead equivalent

material.

4.2.9.3 Persons who cannot be removed from the room shall be protected from the direct scatter

radiation by whole body protective barriers of 0.25 mm lead equivalent and when feasible shall be so

positioned that the nearest portion of the body is a least 2 meters from both the tube head and the nearest

edge of the image receptor.

4.2.9.4 When a portion of the body of any staff or ancillary personnel is potentially subjected to stray

radiation which could result in that individual receiving one quarter of the maximum permissible dose as

defined in RHB 3.4 of these regulations, additional protective devices may be required by the Department.

4.2.10 Shielding of not less than 0.5 mm lead equivalent material shall be used for patients during x-ray

procedures except in cases where the shielding would interfere with the diagnostic image desired.

4.2.11 Individuals shall not be exposed to the useful beam of electronically produced ionizing radiation

except for healing arts purposes, and unless such exposure has been authorized by a licensed practitioner

of the healing arts. This provision specifically prohibits deliberate exposure for the following purposes:

4.2.11.1 Exposure of an individual for training, demonstration or other purposes unless there are also

healing arts requirements and proper prescription has been provided. Demonstrations or training on new x-

ray equipment must be performed with proper protection of the observers and operator(s). Phantoms, not

humans, must be used for demonstrations and training.

4.2.11.2 Healing arts screening. Any person proposing to conduct a healing arts screening program

shall not initiate such a program without prior approval of the Department. When requesting such approval,

that person shall submit the information outlined in Appendix A of this part. If any information submitted

to the Department becomes invalid or outdated, the Department shall be notified within 15 days. Approval

to conduct a healing arts screening program shall be renewed on an annual basis if deemed necessary by

the Department.

4.2.12 When a patient or film must be provided with auxiliary support during a radiation exposure:

4.2.12.1 Mechanical holding devices shall be used when the technique permits.

4.2.12.2 The facility shall indicate the requirements for selecting a holder, and the procedure the

holder shall follow.

4.2.12.3 The human holder shall be instructed in personal radiation safety and shall be protected as

required by 4.2.9.

4.2.12.4 No person shall be used routinely to hold patients or film. All requirements of RHB 4.2.14

and 4.2.15 apply.

4.2.12.5 In those cases where the patient must hold the film, except during intraoral examinations,

any portion of the body other than the area of clinical interest struck by the useful beam shall be protected

by not less than 0.5 mm lead equivalent material.

4.2.12.6 When practical, a pregnant female shall not be used to hold film or patients.

4.2.12.7 Each facility shall have leaded aprons and gloves available in sufficient numbers to provide

protection to all personnel who are involved in x-ray operations who are not otherwise shielded.

4.2.13 Procedures and auxiliary equipment designed to minimize patient and personnel exposure shall

be used.

4.2.13.1 The speed of the screen and film combinations used shall be the fastest speed consistent with

the diagnostic objective of the examinations. Film cassettes without intensifying screens shall not be used

for any routine diagnostic radiological imaging. The film cassettes shall provide good contact between the

intensifying screens and the film.

4.2.13.2 The radiation exposure to the patient shall be the minimum exposure required to produce

images of good diagnostic quality. Appendix D provides patient exposures that are typical of good practices.

These shall be used by the registrant in evaluating patient exposure.

4.2.13.3 Portable or mobile x-ray equipment shall be used only for examinations where it is

impractical to transfer the patient(s) to a stationary x-ray installation. Portable or mobile dental equipment,

not to include handheld, shall be exempt from this regulation.

4.2.13.4 Radiologic technologists performing fluoroscopy as a localizing procedure shall be

monitored by the supervising radiologist who is personally and immediately available.

4.2.14 Personnel Monitoring

4.2.14.1 All persons who are associated with the operation of an X-ray system are subject to the

occupational exposure limits and the requirements for the determination of the doses which are stated in

RHB 3.4. In addition, the following requirements are made:

4.2.14.1.1 When protective clothing or devices are worn on portions of the body and a personnel

monitoring device(s) is required, at least one such device shall be utilized as follows:

4.2.14.1.2 When an apron is worn, and one monitoring device is worn, the monitoring device shall

be worn at the collar outside of the apron. If more than one monitoring device is worn, the devices shall be

worn in accordance with RHB 3.12.5.

4.2.14.1.3 The dose to the whole body based on the maximum dose attributed to any one critical

organ shall be recorded in the reports required by RHB 3.22. If more than one device is used and a record

is made of the data, each dose shall be identified with the area where the device was worn on the body.

4.2.14.2 Exposure of a personnel monitoring device to falsely indicate a dose delivered to an

individual is prohibited.

4.2.14.3 When an individual who has been given responsibility that involves occupational exposure

to x-rays declares that she is pregnant, the employer must, at her request, provide her with an additional

personnel monitoring device to be worn on the trunk underneath the leaded apron, when such apron is worn.

4.2.15 X-ray Log.

4.2.15.1 Each facility shall keep an x-ray log containing the patient's name; the type of examination,

given by title as denoted on the technique chart; identification of the operator performing the examination;

and the dates the examinations were performed.

4.2.15.2 When the examination is performed using any type of fluoroscopy, the log shall include a

record of the amount of time that fluoroscopy was performed or the number of times that the cumulative

timer was reset. The fluoroscopy time is not required to be recorded for radiation therapy simulation units

or instrument guided radiation therapy units.

4.2.15.3 X-ray log records shall be maintained for two years or until the next Department inspection,

whichever is later.

4.2.15.4 Logs are not required for dental or veterinary x-ray equipment.

4.2.16 Quality Assurance

4.2.16.1 Each registrant covered under RHB 4.5 through 4.12 must have "Equipment Performance

Tests" performed on each x-ray unit. The registrant is required to meet the minimum performance criteria

and test frequency. Facilities utilizing x-ray equipment for teaching or demonstration purposes only are

exempt from this Part. Appendix F provides the required minimum performance criteria that must be tested.

Equipment performance tests results must include numerical data. Items found to be non-compliant during

such testing shall be corrected within sixty (60) days of receipt of the report. Records showing the test

results and the correction of any non-compliant items found must be retained for five years or until the next

Department inspection, whichever is later. Equipment performance tests are to be performed:

4.2.16.1.1 At the time installation at all facilities, including veterinary facilities, or

4.2.16.1.2 Within thirty (30) days of installation, provided that the manufacturer’s specified testing

is performed at the time of installation and before patient use.

4.2.16.1.3 At the following specified intervals thereafter:

4.2.16.1.3.1 Dental intraoral and dental extraoral units shall be tested every two years. Dental

computed tomography and dental handheld units shall be tested annually.

4.2.16.1.3.2 All medical x-ray equipment, including fluoroscopic, computed tomography, and

radiation therapy simulators, shall be tested annually. Self calibrating bone densitometry systems are

exempt from this requirement. Mammography units shall meet the requirements of Part V.

4.2.16.1.3.3 Veterinary facilities are required to have equipment performance tests performed at

the time of installation, every five years, and at any time the Department deems necessary.

4.2.16.1.4 On any unit expected to remain at a facility for more than thirty (30) calendar days. If a

unit is expected to remain at a facility for less than thirty (30) calendar days, the manufacturer’s specified

testing must be performed, at a minimum, prior to patient use. Mammography units shall meet the

requirements of Part V.

4.2.16.2 The darkroom shall be light tight to the dark adapted eye and use proper safelighting such

that a film exposed to x-radiation sufficient to produce an optical density from 1 to 2 when processed shall

not suffer an increase in density greater than 0.1 when exposed in the darkroom for 2 minutes with all

safelights on. If used, daylight film handling boxes shall preclude fogging of the film.

4.2.16.3 If grids are used between the patient and the image receptor to decrease scatter to the film

and improve contrast the grid shall:

4.2.16.3.1 Be positioned properly, i.e., tube side facing the right direction, and grid centered to the

central ray,

4.2.16.3.2 If of the focused type, be of the proper focal distance for the SID's being used.

4.2.16.4 Repeat Analysis.

4.2.16.4.1 Each registrant shall establish a repeat analysis program. An analysis of repeats shall

include, at a minimum, the overall repeat rate and the causes for the repeats.

4.2.16.4.2 The repeat analysis shall be done at least quarterly. Records shall be maintained for two

years or until the next Department inspection, whichever is later.

4.2.16.4.3 Facilities with a single operator may document reasons for repeats on the patient log in

lieu of a repeat analysis rate.

4.2.16.4.4 Registrants possessing dental or veterinary x-ray equipment are exempt from this

requirement.

4.2.17 X-ray Film Processing. Each installation using a radiographic x-ray system and using analog

imaging systems (radiographic film) shall have available suitable equipment for handling and processing

radiographic film in accordance with the following provisions:

4.2.17.1 Manual Film Processing Systems

4.2.17.1.1 Processing tanks shall be constructed of mechanically rigid, corrosion resistant

material.

4.2.17.1.2 A dedicated darkroom thermometer shall be used. The thermometer shall be used to

adjust the film processing time according to solution temperature.

4.2.17.1.3 A dedicated darkroom timer with an adjustable preset function shall be used. The timer

shall be used to adjust film processing time according to solution temperature.

4.2.17.1.4 Documentation shall be kept of the frequency at which film processing chemicals are

changed. At a minimum, the interval as recommended by the chemical manufacturer shall be used.

4.2.17.1.5 Safelight. If a safelight is used, it shall be adequate for the film speed(s) and the

darkroom operating procedures used to prevent fogging of unprocessed film.

4.2.17.1.6 The temperature of solutions in the tanks shall be maintained within the range of 60 F

to 80 F (16 C to 27 C). Film shall be developed in accordance with the time-temperature relationships

recommended by the film manufacturer, or, in the absence of such recommendations, with the following

time-temperature chart:

TIME TEMPERATURE CHART

Thermometer Reading

(Degrees)

Minimum Developing

Time (Minutes)

C F

26.7 80 2

26.1 79 2

25.6 78 2 ½

25.0 77 2 ½

24.4 76 3

23.9 75 3

23.3 74 3 ½

22.8 73 3 ½

22.2 72 4

21.7 71 4

21.1 70 4 ½

20.6 69 4 ½

20.0 68 5

19.4 67 5

18.9 66 5 ½

18.3 65 6

17.8 64 6 ½

17.2 63 7

16.7 62 8

16.1 61 8 ½

15.6 60 9 ½

4.2.17.1.7 Radiographs shall not be "sight developed."

4.2.17.2 Automated Processors and Other Closed Processing Systems.

4.2.17.2.1 The temperature of film processing chemicals shall be appropriate for the type of film(s)

being processed at the film transport speed selected.

4.2.17.2.2 The film processing chemicals used and their replenishing rate (if applicable) shall be

appropriate for the film transport speed selected.

4.2.17.2.3 Documentation shall be kept of the frequency at which film processing chemicals are

changed. At a minimum, the interval recommended by the chemical manufacturer shall be used.

4.2.17.2.4 Safelight. If a safelight is used, it shall be adequate for the film speed(s) and the

darkroom operating procedures used to prevent fogging of unprocessed film.

4.2.17.2.5 Films shall be developed in accordance with the time-temperature relationships

recommended by the film manufacturer, or, in the absence of such recommendations, the film shall be

developed using the following chart:

Developer

Temperature

Minimum Immersion

Time *

C F Seconds

35 95 20

34 94 21

34 93 22

33 92 23

33 91 24

32 90 25

*Immersion time only, no crossover time included.

4.2.17.2.6 The specified developer temperature shall be available.

4.2.17.2.7 The sensitometric performance of an automatic processor shall be equivalent to other

operating processor models set up to meet the above developer temperature and immersion time

specifications. This is determined by processing identically exposed film through each model and

comparing the results.

4.2.17.2.8 Densitometric and sensitometric performance testing.

4.2.17.2.8.1 Densitometric and sensitometric performance testing of the processor is required of

facilities that process more than 250 films per week.

4.2.17.2.8.2 Control limits shall be established for each parameter monitored. Provisions for

correctable action shall be undertaken whenever the pre-established control limits are exceeded.

4.2.17.2.8.3 Documentation of testing must be maintained for at least two years or until the next

Department inspection, whichever is later.

4.2.17.2.8.4 Facilities processing more than 250 films per day are required to perform this testing

on each day that examinations are performed before any clinical films are processed that day.

4.2.17.2.8.5 Facilities that operate 24 hours per day must perform the required testing once each

day.

4.2.17.2.8.6 Registrants possessing dental or veterinary x-ray equipment are exempt from this

requirement.

4.2.17.2.9 Records of processor maintenance shall be kept for at least two years or until the next

Department inspection, whichever is later.

4.2.17.3 Other Requirements

4.2.17.3.1 Film pass boxes, if provided, shall be so constructed as to exclude light when film is

placed in or removed from the boxes, and shall incorporate adequate shielding to prevent exposure of

undeveloped film to stray radiation.

4.2.17.3.2 Film shall be stored in a cool, dry place and shall be protected from exposure to stray

radiation. Film in open packages shall be stored in a light tight container.

4.2.17.3.3 Film cassettes and intensifying screens shall be inspected in accordance with the

facility's approved procedures and shall be cleaned and replaced as necessary to best assure radiographs of

good diagnostic quality. Documentation of this periodic inspection and cleaning must be maintained for at

least two years or until the next Department inspection, whichever is later.

4.2.17.4 Outdated x-ray film shall not be used for human diagnostic radiographs, unless the film has

been stored in accordance with the manufacturer's recommendations and a sample of the film passes a

sensitometric test for normal ranges of base fog and speed.

4.2.17.5 Film developing solutions shall be prepared in accordance with the directions given by the

manufacturer, and shall be maintained in strength by replenishment or renewal so that full development is

accomplished within the time specified by the manufacturer.

RHB 4.3 General Requirements for all Diagnostic X-ray Systems. All diagnostic x-ray systems shall meet

the following requirements.

4.3.1 Warning Label. The control panel containing the main power switch shall bear the warning

statement: "WARNING: This x-ray unit may be dangerous to patient and operator unless safe exposure

factors and operating instructions are observed."

4.3.1.1 The warning label shall be legible and its view unobstructed.

4.3.2 Battery Charge Indicator. On battery-powered generators, visual means shall be provided on the

control panel to indicate that the battery is adequately charged.

4.3.3 Leakage Radiation from the Diagnostic Source Assembly. The leakage radiation from the

diagnostic source assembly measured at a distance of 1 meter in any direction from the source shall not

exceed 100 milliRoentgen in 1 hour when the X-ray tube is operated at its maximum technique factors.

4.3.4 Radiation from Capacitor Energy Storage Equipment in Standby Status. Radiation emitted from

the X-ray tube when the exposure switch or timer is not activated shall not exceed a rate of 2 milliRoentgen

per hour at five (5) centimeters from any accessible surface of the diagnostic source assembly, with the

beam limiting device fully open.

4.3.5 Beam Quality. The half-value layer (HVL) of the useful beam for a given x-ray tube potential

shall not be less than the values shown in Table I. If it is necessary to determine such half-value layer at an

X-ray tube potential that is not listed in Table I, linear interpolation or extrapolation may be made.

TABLE I

Design Operating

Range (kVp)

Measured Potential

(kVp)

Specified Dental

Systems (mm Al)

All other Diagnostic

(mm Al)

30 to 50 30 N/A 0.3

40 N/A 0.4

50 1.5 0.5

51 to 70 51 1.5 1.2

60 1.5 1.3

70 1.5 1.5

Above 70 71 2.1 2.1

80 2.3 2.3

90 2.5 2.5

100 2.7 2.7

110 3.0 3.0

120 3.2 3.2

130 3.5 3.5

140 3.8 3.8

150 4.1 4.1

4.3.5.1 Beryllium window tubes shall have a minimum of 0.5 mm aluminum equivalent filtration

permanently mounted in the useful beam.

4.3.5.2 For capacitor energy storage equipment, compliance with RHB 4.3.5 shall be determined with

the maximum quantity of charge per exposure.

4.3.5.3 The required minimal half-value layer of the useful beam shall include the filtration contributed

by all materials which are permanently between the source and the patient.

4.3.5.4 All intraoral dental units manufactured after December 1, 1980 shall have at least 1.5

millimeters aluminum equivalent filtration permanently installed in the useful beam.

4.3.6 Filtration Controls. For x-ray systems which have variable kVp and variable filtration for the

useful beam, a device shall link the kVp selector with the filter(s) and shall prevent an exposure unless the

minimum amount of filtration required by RHB 4.3.5 is in the useful beam for the given kVp which has

been selected.

4.3.7 Multiple Tubes. Where two or more radiographic tubes are controlled by one exposure switch,

the tube or tubes which have been selected shall be clearly indicated prior to initiation of the exposure.

4.3.7.1 This indication shall be on both the X-ray control and at or near the tube housing assembly.

4.3.8 Mechanical Support of Tube Head. The tube housing assembly supports shall be adjusted such

that the tube housing assembly will remain stable during an exposure unless the tube housing movement is

a designed function of the X-ray system.

4.3.9 Technique Indicators

4.3.9.1 The technique factors, whether manual or automatic exposure control, shall be indicated before

the exposure begins. This requirement may be met by permanent markings on equipment having fixed

technique factors.

4.3.9.2 Technique factors shall be visible from the operator's position except in the case of spot films

made by the fluoroscopist.

4.3.9.3 The x-ray control shall provide visual indication of the production of x-rays.

4.3.9.4 X-ray systems utilizing arbitrary number or letter designators for kVp, time and milliAmperage

shall be accompanied by a chart giving the value of physical factors for each arbitrary designator.

4.3.10 Focal Spot Indication. The focal spot shall be denoted in such a manner and area as to be easily

seen on the tube housing.

4.3.11 Mechanical Timers. Use of mechanical timers is prohibited.

4.3.12 Imaging Systems other than Screen/Film. The provisions of this part are in addition to, and not in

substitution for, applicable provisions of these regulations.

4.3.12.1 Users of digital imaging acquisition systems shall follow protocol established by the

manufacturer of the digital imaging acquisition system. Records documenting adherence to this protocol

shall be kept for at least two years or until the next Department inspection, whichever is later.

4.3.12.2 The manufacturer’s current operating manual shall be available for Department review.

RHB 4.4 Shielding.

4.4.1 Shielding Plan Required.

4.4.1.1 Prior to construction of a new facility, modification, or renovation of an existing x-ray facility,

or replacement of an x-ray machine, the floor plans and equipment arrangement shall be reviewed by a

Class III, Class IV, Class VII, or Class IX vendor and submitted to the Department for review and

acceptance.

4.4.1.2 A shielding plan shall be required for any space utilized as a radiation area for a period of

greater than five (5) consecutive days.

4.4.2 Equipment Replacement.

4.4.2.1 A shielding plan is not required upon the replacement of an existing x-ray machine, control, or

generator with like equipment and when there are no other changes which would render the original

shielding plan inaccurate, as determined by a Class III, Class IV, Class V, Class VII, Class VIII or Class

IX vendor. The appropriate vendor shall notify the Department regarding such replacement. A form shall

be provided by the Department for this notification and shall be exempt from RHB 2.3.2.

4.4.2.2 A shielding plan shall be required when a facility replaces an existing x-ray machine or control

generator with a unit with increased capabilities which would render the original shielding plan inaccurate,

as determined by a Class III, Class IV, Class V, Class VII, Class VIII or Class IX vendor, or when the

original shielding plan is not available.

4.4.2.3 A shielding plan shall be required when the parameters of the original shielding plan change

to an extent so as to render the original shielding plan inaccurate, as determined by a Class III, Class IV,

Class V, Class VII, Class VIII or Class IX vendor.

4.4.3 X-ray equipment shall not be installed or operated before a shielding plan for the unit has been

reviewed and accepted by the Department.

4.4.4 Shielding Plan Requirements.

4.4.4.1 The registrant shall submit plans and a report, including any recommendations and all basic

assumptions used, from the vendor to the Department. Applicable fees shall be submitted in accordance

with RHB 2.3.2. In order for the Department to accept the submitted shielding plan, the information listed

in Appendix B shall be submitted. The design considerations listed in Appendix C shall be followed.

4.4.4.2 Each installation shall be provided with such primary barriers and secondary barriers as are

necessary to assure compliance with RHB 3.3, RHB 3.4 and RHB 3.5. The requirement shall be deemed to

be met if the thickness of such barriers is equivalent to the thickness as computed in accordance with the

National Council of Radiation Protection and Measurements, Report Number 147, “Structural Shielding

Design for Medical X-ray Imaging Facilities;” the National Council of Radiation Protection and

Measurements, Report Number 145, “Radiation Protection in Dentistry;” the National Council of Radiation

Protection and Measurements, Report Number 151, “Structural Shielding Design and Evaluation for

Megavoltage X- and Gamma-Ray Radiotherapy Facilities,” or an equivalent reference.

4.4.4.3 All wall, floor, and ceiling areas exposed to the useful beam shall have primary barriers.

Primary barriers in walls shall extend to a minimum height of 2.13 meters above the floor.

4.4.4.4 Secondary barriers shall be provided in all wall, floor and ceiling areas not having primary

barriers.

4.4.4.5 The operator's station at the control shall be behind a protective barrier either in a separate

room, in a protected booth, or behind a shield which will intercept the useful beam and any radiation that

has been scattered only once.

4.4.4.6 Mobile and portable x-ray systems used in conjunction with a permanently installed cassette

holder shall be considered a stationary radiographic system and shall meet the requirements for such an

installation.

4.4.5 The acceptance of such plans shall not preclude the requirement of additional modifications

should a subsequent analysis of operating conditions indicate the possibility of an individual receiving a

dose in excess of the limits prescribed in Part III of these regulations.

4.4.6 Area Surveys. The registrant shall have a radiation area survey performed by a Class V, Class

VII, or Class IX vendor, registered with the Department.

4.4.6.1 The survey shall be submitted to the Department for review and shall include a scale drawing

of the room indicating the composition of the walls, floor, ceiling, windows, and doors, and the placement

of the x-ray equipment, including the table, control, and vertical cassette holder, if provided. The location

and composition of the film bin shall also be included. The survey shall include an evaluation of the

adequacy of each protective barrier, the operator's location, and the film storage area, if appropriate.

4.4.6.2 A copy of the radiation area survey shall be submitted to the Department within thirty days

after installation of the x-ray equipment.

4.4.6.3 Any deviation from the accepted shielding plan shall be documented and evaluated for

adequacy.

4.4.6.4 The Department may determine that a survey is not required for some installations.

4.4.7 “As-built” Drawings.

4.4.7.1 Within 30 days after construction and installation are complete, the facility shall ensure that

"as-built" drawings are submitted to the Department. The drawings must indicate the composition of the

walls, floor, ceiling, windows and doors. The drawings must also indicate the placement of the x-ray

equipment, including the table, control, and vertical cassette holder, if provided, as well as the location and

composition of the film bin, if present.

4.4.7.2 Any deviation from the accepted shielding plan shall be documented and evaluated for

adequacy by a Class III, Class IV, Class VII, or Class IX vendor.

4.4.8 Bone Density And Mammography Installations.

4.4.8.1 Prior to installation of new or replacement equipment:

4.4.8.1.1 A shielding plan shall be submitted to the Department for review and acceptance or;

4.4.8.1.2 A written request shall be made by a Class V, Class VII, or Class IX vendor registered

with the Department to perform a post-install survey in lieu of a shielding plan. All provisions of RHB 4.4.6

apply.

4.4.8.1.3 Applicable fee shall be submitted in accordance with RHB 2.3.2.

4.4.9 After installation of a radiation machine, the facility shall maintain for inspection by the

Department:

4.4.9.1 A copy of the shielding plan, as required by RHB 4.4,

4.4.9.2 A copy of the Department’s acceptance letter, and

4.4.9.3 A copy of the area survey or “as-built” drawing, as required by RHB 4.4.6 or 4.4.7.

RHB 4.5 Intraoral Dental Radiographic Installations. In addition to the provisions of RHB 4.3, the

requirements of RHB 4.5 apply to x-ray equipment and associated facilities used for dental radiography.

4.5.1 Source to Skin Distance (SSD). X-ray systems designed for use with an intraoral image receptor

shall be provided with means to limit the source-to-skin distance, to not less than eighteen (18) centimeters.

4.5.2 Field Limitation. Radiographic systems designed for use with an intraoral image receptor shall

be provided with means to limit the x-ray field such that:

4.5.2.1 The x-ray field at the minimum SSD shall be containable in a circle having a diameter of no

more than 7 centimeters.

4.5.2.2 An open ended Position Indication Device (PID) shall be used, and shall provide the same

degree of protection as the housing. Pointed PIDs shall not be used.

4.5.2.3 The operator shall position the end of the PID as close as practicable to the skin of the patient.

4.5.3 Timers. Means shall be provided to terminate the exposure at a preset time interval, preset product

of current and time, a preset number of pulses, or a preset radiation exposure to the image receptor. In

addition:

4.5.3.1 It shall not be possible to make an exposure when the timer is set to a "zero" or "off" position

if either position is provided.

4.5.3.2 Termination of an exposure shall cause automatic resetting of the timer to its initial setting or

to "Zero".

4.5.3.3 Timer reproducibility. The average exposure period ( T ) shall be greater than or equal to 5

times the maximum exposure period (Tmax) minus the minimum exposure period (Tmin) when 4 timer

tests are performed: T ≥ 5 (Tmax - Tmin).

4.5.4 X-ray Control.

4.5.4.1 An x-ray control shall be incorporated into each x-ray system such that an exposure can be

terminated by the operator at any time, except for exposures of one-half (1/2) second or less.

4.5.4.2 Each x-ray control shall be located in such a way as to meet the following requirements:

4.5.4.2.1 Stationary x-ray systems installed after July 1, 1993, shall have the x-ray control

permanently mounted in a protected area, so that the operator is required to remain in that protected area

during the entire exposure; and

4.5.4.2.2 For stationary x-ray systems without a protected area and installed before July 1, 1993,

the exposure switch shall be such that the operator shall stand at least six feet away from the tube housing

and out of the direct beam.

4.5.4.2.3 For mobile and portable x-ray systems, the exposure switch shall meet the requirements

of 4.5.4.2.2.

4.5.4.2.4 Visual and/or audible indication, observable at or from the operator's protected position,

shall be provided whenever x-rays are initiated and terminated.

4.5.5 Exposure Reproducibility. The coefficient of variation shall not exceed 0.05 when all selectable

technique factors are held constant. This requirement shall be deemed to have been met if, when 4 exposures

are made at identical technique factors, the value of the average exposure ( E ) is greater than or equal to 5

times the maximum exposure (Emax) minus the minimum exposure (Emin): E ≥ 5 (Emax - Emin).

4.5.6 Linearity. When the equipment allows a choice of x-ray tube current settings and is operated on

a power supply as specified by the manufacturer for any fixed x-ray tube potential within the maximum

rating, the average ratios of exposure to the indicated milliAmpere-seconds product obtained at any two

tube current settings shall not differ by more than 0.10 times their sum: [X1 - X2] < 0.10 (X1 + X2) where

X1 and X2 are the average mR/mAs values obtained at each of the two tube current settings.

4.5.7 Accuracy. Deviation of technique factors from indicated values shall not exceed the limits

specified for that system by the manufacturer. In the absence of manufacturer's specifications the deviation

shall not exceed 10% of the indicated value.

4.5.8 kVp limitations. Dental x-ray machines with a nominal fixed kVp of less than 50 kVp shall not

be used to make diagnostic dental radiographs of humans.

4.5.9 Multiple Tubes. Where two or more radiographic tubes are controlled by one exposure switch,

the tube or tubes which have been selected shall be clearly indicated prior to initiation of the exposure. This

indication shall be both on the X-ray control and at or near the tube housing which has been selected.

4.5.10 Mechanical Support of Tube Head. The tube housing assembly supports shall be adjusted so that

the tube housing assembly will remain stable during an exposure unless the tube housing movement is a

designed function of the X-ray system.

4.5.11 Structural Shielding.

4.5.11.1 Dental rooms containing x-ray machines shall be provided with primary and secondary

barriers for all areas struck by the useful beam, as required by RHB 4.4.4.2.

4.5.11.2 When dental x-ray units are installed in adjacent rooms or areas, protective barriers shall be

provided between the rooms or areas.

4.5.11.3 Pass throughs between adjacent areas shall be securely interlocked in a functional, permanent

manner.

4.5.11.4 Shielding plans are not required for intraoral dental radiographic installations.

4.5.12 Operating Procedures.

4.5.12.1 Neither the dentist nor his assistant shall hold patients or films during exposure, nor shall

any individual be regularly used for this service.

4.5.12.2 The tube housing and the PID shall not be hand-held during an exposure.

4.5.12.3 Dental fluoroscopy without image intensification shall not be used.

4.5.12.4 Each patient undergoing dental radiography shall be draped with a protective apron of not

less than 0.25 millimeter lead equivalent to cover the gonadal area unless the patient refuses.

4.5.12.5 Only persons required for the radiographic procedure shall be in the radiographic room

during exposures.

RHB 4.6 Extraoral Dental Radiographic Installations.

4.6.1 Cephalometric Installations

4.6.1.1 All provisions of RHB 4.4 and 4.7 apply.

4.6.1.2 The radiographic field shall be restricted to the area of the image receptor.

4.6.2 Panoramic Installations

4.6.2.1 All provisions of RHB 4.5 apply, except 4.5.1 and 4.5.2.1.

4.6.3 Dental CT

4.6.3.1 Where applicable, all provisions of RHB 4.4 and 4.11 apply, except RHB 4.11.2.3.

4.6.4 Hand-Held Intraoral Equipment

4.6.4.1 The hand-held x-ray system shall be equipped with a non-removable backscatter shield of not

less than 0.25 mm lead equivalent and 15.2 cm (6 inches) in diameter that is positioned as close as

practicable to the distal end of the position indication device.

4.6.4.2 The facility shall maintain documentation that each operator has completed training as

specified by the manufacturer, and approved by the Department.

4.6.4.3 The facility shall adopt and follow protocols provided by the manufacturer and approved by

the Department regarding the safe operation of the device.

4.6.4.4 When operating a hand-held intraoral dental radiographic unit, operators shall wear a 0.25 mm

lead equivalent apron and thyroid collar.

4.6.4.5 If the operator has difficulty in holding the device stationary during the exposure, the operator

shall use a stand to immobilize the device.

4.6.4.6 The registrant shall secure the hand-held device from unauthorized removal or use.

RHB 4.7 Medical Radiographic Systems. The requirements of this Part apply to x-ray equipment and

associated facilities used for radiography with stationary radiographic systems other than intraoral dental,

fluoroscopic, computed tomography (CT), mammography or veterinary medical systems.

4.7.1 Stationary General Purpose Units. In addition to the other provisions of this part, all stationary

general purpose units must also meet the following requirements:

4.7.1.1 Means shall be provided for independent stepless adjustment of at least two dimensions of the

x-ray field.

4.7.1.2 Means shall be provided to indicate when the axis of the x-ray beam is perpendicular to the

plane of the image receptor.

4.7.1.3 Means shall be provided for visually defining the perimeter of the X-ray field. The total

misalignment of the edges of the visually defined field with the respective edges of the X-ray field along

either the length or width of the visually defined field shall not exceed two percent (2%) of the distance

from the source to the center of the visually defined field when the surface upon which it appears is

perpendicular to the axis of the X-ray beam.

4.7.1.4 The beam limiting device shall indicate numerically the field size in the plane of the image

receptor to which it is adjusted.

4.7.1.5 Indication of field size dimensions and SID's used shall be specified in inches and/or

centimeters on the collimator. The indications on the collimator shall be such that aperture adjustments

result in X-ray field dimensions in the plane of the image receptor which correspond to those of the image

receptor to within two percent (2%) of the SID when the beam axis is perpendicular to the plane of the

image receptor.

4.7.1.6 The beam limiting device shall be provided with SID scales that reflect the actual SID(s) used

for radiographic procedures.

4.7.1.7 Means shall be provided to align the center of the x-ray field with the center of the image

receptor to within 2 percent of the SID.

4.7.2 X-ray Systems Designed for One Image Receptor Size. Radiographic equipment designed for

only one image receptor size at a fixed SID shall be provided with means to limit the field at the plane of

the image receptor, and to align the center of the x-ray field with the center of the image receptor to within

two percent (2%) of the SID, or shall be provided with means to both size and align the x-ray field such

that the x-ray field at the plane of the image receptor does not extend beyond any edge of the image receptor.

4.7.3 Special Purpose X-ray Systems. In addition to the other provisions of this Part, all special purpose

x-ray systems shall also meet the following requirements:

4.7.3.1 Means shall be provided to limit the x-ray field in the plane of the image receptor such that the

x-ray field does not exceed each dimension of the image receptor by more than 2% of the SID when the

axis of the x-ray beam is perpendicular to the plane of the image receptor.

4.7.3.2 Means shall be provided to align the center of the X-ray field with the center of the image

receptor to within two percent (2%) of the SID, or means shall be provided to both size and align the x-ray

field such that the x-ray field at the plane of the image receptor does not extend beyond any edge of the

image receptor. Compliance shall be determined with the axis of the x-ray beam perpendicular to the plane

of the image receptor.

4.7.3.3 The above RHB 4.7.3.1 and 4.7.3.2 may be met with a system that meets the requirements for

a general purpose X-ray system as specified in Part RHB 4.7.3, above or, when alignment means are also

provided, may be met with either:

4.7.3.3.1 An assortment of removable, fixed aperture, beam limiting devices sufficient to meet the

requirement for each combination of image receptor size and SID for which the unit is designed. Each such

device shall have clear and permanent markings to indicate the image receptor size and SID for which it is

designed; or

4.7.3.3.2 A beam limiting device having multiple fixed apertures sufficient to meet the requirement

for each combination of image receptor size and SID for which the unit is designed. Permanent, clearly

legible markings shall indicate the image receptor size and SID for which each aperture is designed and

shall indicate which aperture is in position for use.

4.7.4 Radiation Exposure Control Devices.

4.7.4.1 Timers. Means shall be provided to terminate the exposure at a preset time interval, preset

product of current and time, a preset number of pulses, or a preset radiation exposure to the image receptor.

In addition, it shall not be possible to make an exposure when the timer is set to a zero or off position if

either position is provided.

4.7.4.2 X-ray Control.

4.7.4.2.1 An x-ray control shall be incorporated into each x-ray system such that an exposure can

be terminated by the operator at any time ("deadman" switch) except for exposures of one-half (1/2) second

or less, or during serial radiography when means shall be provided to permit completion of any single

exposure of the series in process.

4.7.4.2.2 Stationary x-ray systems shall have the x-ray control permanently mounted in a protected

area so that the operator is required to remain in that protected area during the entire exposure.

4.7.4.2.3 The X-ray control shall provide visual indication observable at or from the operator

protected position whenever X-rays are produced. In addition, a signal audible to the operator shall indicate

that the exposure has terminated.

4.7.4.2.4 The X-ray control shall be so placed that the operator can view the patient during any

exposure and still stand in a protected area.

4.7.4.2.5 Automatic Exposure Controls. When an automatic exposure control is provided:

4.7.4.2.5.1 Indication shall be made on the control panel when this mode of operation is selected;

4.7.4.2.5.2 If the x-ray tube potential is equal to or greater than 50 kVp, the minimum exposure

time for field emission equipment rated for pulsed operation shall be equal to or less than a time interval

equivalent to 2 pulses;

4.7.4.2.5.3 The minimum exposure time for all equipment other than that specified in 4.7.4.2.5.2

shall be equal to or less than one-sixtieth (1/60) second or a time interval required to deliver 5 mAs,

whichever is greater;

4.7.4.2.5.4 Either the product of peak x-ray tube potential, current, and exposure time shall be

limited to not more than 60 kWs per exposure, or the product of x-ray tube current and exposure time shall

be limited to not more than 600 mAs per exposure except that, when the x-ray tube potential is less than 50

kVp, the product of x-ray tube current and exposure time shall be limited to not more than 2000 mAs per

exposure; and

4.7.4.2.5.5 A visible signal shall indicate when an exposure has been terminated at the limits

required by 4.7.4.2.5.4, and manual resetting shall be required before further automatically timed exposures

can be made.

4.7.4.2.6 Timer Reproducibility. With a timer setting of 0.5 second or less, the average exposure

period ( T ) shall be greater than or equal to 5 times the maximum exposure period (Tmax) minus the

minimum exposure period (Tmin) when 4 timer tests are performed: T ≥ 5 (Tmax - Tmin).

4.7.5 Exposure Reproducibility. The coefficient of variation of exposure shall not exceed 0.05 when

all selectable technique factors are held constant. This requirement shall be deemed to have been met if,

when four exposures are made at identical technique factors, the value of the average exposure ( E ) is

greater than or equal to 5 times the maximum exposure (Emax) minus the minimum exposure (Emin): E

≥ 5 (Emax - Emin).


specified for that system by its manufacturer. In the absence of manufacturer's specifications, the deviation


4.7.7 Linearity. The following requirements apply when the equipment is operated on a power supply

as specified by the manufacturer for any fixed x-ray tube potential within the range of 40 percent to 100

percent of the maximum rated.

4.7.7.1 Equipment having independent selection of x-ray tube current (mA). The average ratios of

exposure to the indicated milliAmpere-seconds product (C/kg/mAs (or mR/mAs)) obtained at any tube

current settings shall not differ by more than 0.10 times their sum. This is: [X1-X2] < 0.10 (X1+X2); where

X1 and X2 are the average C/kg/mAs (or mR/mAs) values obtained at any two tube current settings.

4.7.7.2 Equipment having a combined x-ray tube current-exposure time product (mAs) selector, but

not a separate tube current (mA) selector. The average ratios of exposure to the indicated milliAmpere-

seconds product (C/kg/mAs (or mR/mAs)) obtained at any two mAs selector settings shall not differ by

more than 0.10 times their sum. This is : [X1-X2] < 0.10 (X1+X2); where X1 and X2 are the average

C/kg/mAs (or mR/mAs) values obtained at any two mAs selector settings.

4.7.7.3 Measuring Compliance. Determination of compliance shall be based on 4 exposures, at each

of the two settings. The two settings may include any two focal spot sizes provided that neither focal spot

size is equal to or less than 0.45 millimeter, in which case the two settings shall be restricted to the same

focal spot size. For purposes of this requirement, focal spot size is the nominal focal spot size specified by

the x-ray tube manufacturer.

4.7.8 Light Localization.

4.7.8.1 When a light localizer is used to define the x-ray field, it shall provide an average illumination

of not less than 15 footcandles at 100 centimeters or at the maximum SID, whichever is less. The average

illumination shall be based upon measurements made in the approximate center of each quadrant of the

light field. Radiation therapy simulation systems manufactured on and after May 27, 1980, are exempt from

this requirement.

4.7.8.2 Exemptions to RHB 4.7.8.1 shall be granted if the registrant demonstrates to the Department

that their equipment is unable to meet these regulations, and the Department determines that patient safety

or image quality is not compromised.

4.7.9 Certified Systems. In addition to the requirements of these rules, the registrant shall not make,

nor cause to be made, any modification of components or installations of components certified pursuant to

US Food and Drug Administration Regulation 21 CFR 1020 "Performance Standards for Ionizing Radiation

Emitting Products" in any manner that could cause the installations or the components to fail to meet the

requirements of the applicable parts of the standards specified in 21 CFR 1020, except where a variance

has been granted by the Director, Center for Devices and Radiological Health, Food and Drug

Administration.

4.7.10 Maintenance Schedule. On all equipment containing components certified pursuant to US Food

and Drug Administration Regulation CFR 1020 "Performance Standards for Ionizing Radiation Emitting

Products" the registrant shall perform, or cause to be performed, the schedule of maintenance provided by

the manufacturer pursuant to 21 CFR 1020.30(h)(l)(ii). A log book of such maintenance shall be maintained

for inspection by the Department.

4.7.11 SID Indication. Means shall be provided to indicate the SID. SIDs shall be indicated in inches

and/or centimeters, and shall be indicated to within 2 percent.

4.7.12 Positive Beam Limitation. For units having an operable positive beam limitation (PBL) system,

the following requirements must be met:

4.7.12.1 Neither the length nor width of the x-ray field shall differ from the corresponding image

receptor dimensions by more than 3 percent of the SID; and

4.7.12.2 The sum of the length and width differences, without regard to sign, shall not exceed 4

percent of the SID.

4.7.12.3 The positive beam limitation system shall be capable of operation, at the discretion of the

operator, such that the size of the field may be made smaller than the size of the image receptor through

stepless adjustment of the field size. The minimum field size at an SID of 100 centimeters shall be equal to

or less than 5 centimeters by 5 centimeters.

4.7.12.4 The positive beam limitation system shall be designed such that if a change in image receptor

does not cause automatic return to positive beam limitation function and any change of image receptor size

or SID must cause the automatic return.

4.7.12.5 PBL compliance shall be determined with the beam axis perpendicular to the plane of the

image receptor. Compliance shall be determined no sooner than 5 seconds after insertion of the image

receptor.

4.7.13 The useful beam shall be limited to the area of clinical interest. This shall be deemed to have been

met if a positive beam limiting device has been properly used or if evidence of collimation has been shown

on at least three sides or three corners of the film, (for example, projections from the shutters of the

collimator, cone cutting at the corners, or borders at the film's edge).

4.7.14 Minimum Field Size. The minimum field size at an SID of 100 cm shall be equal to or less than

5 centimeters by 5 centimeters.

RHB 4.8 Mobile Radiographic Equipment.

4.8.1 All provisions of RHB 4.7.4 through 4.7.14 apply, except 4.7.12 and 4.7.4.2.2.

4.8.2 Means shall be provided for independent stepless adjustment of at least two dimensions of the x-

ray field.

4.8.3 Means shall be provided to indicate when the axis of the x-ray beam is perpendicular to the plane


4.8.4 Means shall be provided for visually defining the perimeter of the X-ray field. The total

misalignment of the edges of the visually defined field with the respective edges of the X-ray field along

either the length or width of the visually defined field shall not exceed two percent (2%) of the distance


perpendicular to the axis of the X-ray beam.

4.8.5 If provided, the beam-limiting device shall indicate numerically the field size in the plane of the

image receptor to which it is adjusted.

4.8.6 If collimator indications are provided, the indications shall be such that aperture adjustments

result in X-ray field dimensions in the plane of the image receptor which correspond to those of the image

receptor to within two percent (2%) of the SID when the beam axis is perpendicular to the plane of the

image receptor.

4.8.7 Means shall be provided to measure SIDs, and shall be accurate to within 2%.

4.8.8 Mobile and portable x-ray systems which are used in a single location for a period of greater than

five consecutive days shall be considered a stationary radiographic system and shall meet the requirements

of RHB 4.4.

4.8.9 Mobile and portable x-ray systems which are used at multiple locations shall be provided with an

adequate protective barrier or protective apron for the operator and with a method of control which will

permit the operator to be at least 6 feet from the tube head and the nearest edge of the useful beam during

exposures.

4.8.10 Personnel monitoring shall be required for all operators of mobile and portable x-ray systems.

4.8.11 Tube stands. A tube stand or other mechanical support shall be used for portable x-ray systems

so that the x-ray tube housing assembly need not be hand-held during exposures.

4.8.12 All mobile or portable radiographic systems shall be provided with means to limit the source-to-

skin distance to equal to or greater than 30 centimeters.

RHB 4.9 Fluoroscopic X-ray Systems. All fluoroscopic x-ray systems shall be image intensified, and meet

the following requirements. The requirements of this part apply to all stationary, portable, mobile, and C-

arm type fluoroscopes.

4.9.1 Source-to-Skin Distance (SSD). The SSD shall not be less than:

4.9.1.1 thirty-eight (38) centimeters on stationary fluoroscopic systems manufactured on or after

August 1, 1974.

4.9.1.2 thirty-five and one half (35.5) centimeters on stationary fluoroscopic systems manufactured

prior to August 1, 1974.

4.9.1.3 thirty (30) centimeters on all mobile and portable fluoroscopes, and

4.9.1.4 twenty (20) centimeters for mobile fluoroscopes used for specific surgical procedures. If

removable, the appropriate spacer shall be replaced after the specific surgical procedure application is

complete.

4.9.1.4.1 For stationary, mobile, or portable fluoroscopes manufactured on or after June 10, 2006,

having a maximum source-image receptor distance of less than forty-five (45) cm, means shall be provided

to limit the source-skin distance to not less than nineteen (19) cm. Such systems shall be labeled for

extremity use only.

4.9.1.4.2 For those systems intended for specific surgical applications that would be prohibited at

the source-skin distance specified above, provisions may be made for operation at shorter source-skin

distances but in no case less than ten (10) cm.

4.9.2 Limitation of Useful Beam.

4.9.2.1 Primary Barrier

4.9.2.1.1 The fluoroscopic imaging assembly shall be provided with a primary protective barrier

which intercepts the entire cross section of the useful beam at any SID.

4.9.2.1.2 The x-ray tube used for fluoroscopy shall not produce x-rays unless the barrier is in

position to intercept the entire useful beam.

4.9.2.2 X-ray field. Neither the length nor the width of the x-ray field in the plane of the image receptor

shall exceed that of the visible area of the image receptor by more than 3 percent of the SID. The sum of

the excess length and the excess width shall be no greater than 4 percent of the SID. In addition:

4.9.2.2.1 Means shall be provided to permit further limitation of the x-ray field. Beam-limiting

devices manufactured after May 22, 1979, and incorporated in equipment with a variable SID and/or a

visible area of greater than 300 square centimeters shall be provided with means for stepless adjustment of

the x-ray field;

4.9.2.2.2 All equipment with a fixed SID and a visible area of 300 square centimeters or less shall

be provided with either stepless adjustment of the x-ray field or with means to further limit the x-ray field

size at the plane of the image receptor to 125 square centimeters or less. Stepless adjustment shall, at the

greatest SID, provide continuous field sizes from the maximum obtainable to a field size of 5 centimeters

by 5 centimeters or less.

4.9.2.2.3 For equipment manufactured after February 25, 1978, when the angle between the image

receptor and beam axis is variable, means shall be provided to indicate when the axis of the x-ray beam is

perpendicular to the plane of the image receptor.

4.9.2.2.4 Compliance shall be determined with the beam axis indicated to be perpendicular to the

plane of the image receptor. For rectangular x-ray fields used with circular image reception, the error in

alignment shall be determined along the length and width dimensions of the x-ray field which pass through

the center of the visible area of the image receptor.

4.9.2.2.5 For uncertified image-intensified fluoroscopic equipment with a spot film device, the x-

ray beam with the shutters fully opened (during fluoroscopy or spot filming) shall be no larger than the

largest spot film size for which the device is designed. Measurements shall be made at the minimum SID

available but at no less than 20 centimeters table top to the film plane distance.

4.9.2.3 Spot film devices which are certified components shall meet the following additional

requirements.

4.9.2.3.1 Means shall be provided between the source and the patient for adjustment of the x-ray

field size in the plane of the film to the size of that portion of the film which has been selected on the spot

film selector. Such adjustment shall be automatically accomplished except when the x-ray field size in the

plane of the film is smaller than that of the selected portion of the film. For spot film devices manufactured

after June 21, 1979, if the x-ray field size is less than the size of the selected portion of the film, the means

for adjustment of the field size shall be only at the operator's option.

4.9.2.3.2 Spot film field size. Neither the length nor the width of the x-ray field in the spot film

plane shall exceed the image receptor by more than 3 percent of the SID. The sum of the excess length and

the excess width shall be no greater than 4 percent of the SID.

4.9.2.3.3 It shall be possible to adjust the x-ray field size in the plane of the film to a size smaller

than the selected portion of the film. The minimum field size at the greatest SID shall be equal to, or less

than, 5 centimeters by 5 centimeters.

4.9.2.3.4 The center of the x-ray field in the plane of the film shall be aligned with the center of the

selected portion of the film to within 2 percent of the SID.

4.9.2.3.5 On spot-film devices manufactured after February 25, 1978, if the angle between the plane

of the image receptor and beam axis is variable, means shall be provided to indicate when the axis of the x-

ray beam is perpendicular to the plane of the image receptor, and compliance shall be determined with the

beam axis indicated to be perpendicular to the plane of the image receptor.

4.9.3 Activation of the Fluoroscopic Tube. X-ray production in the fluoroscopic mode shall be

controlled by a device which requires continuous pressure by the fluoroscopist for the entire time of any

exposure. When recording serial fluoroscopic images, the fluoroscopist shall be able to terminate the x-ray

exposure(s) at any time, but means may be provided to permit completion of any single exposure of the

series in process.

4.9.4 Exposure Rate Limits. Entrance Exposure Rate Allowable Limits.

4.9.4.1 For equipment manufactured prior to May 19, 1995:

4.9.4.1.1 Equipment with automatic exposure rate control. Fluoroscopic equipment which is

provided with automatic exposure rate control shall not be operable at any combination of tube potential

and current which will result in an exposure rate in excess of 10 Roentgens (2.58 mC/kg) per minute at the

point where the center of the useful beam enters the patient, except:

4.9.4.1.1.1 During recording of fluoroscopic images, or

4.9.4.1.1.2 When an optional high level control is provided. When so provided, the equipment

shall not be operable at any combination of tube potential and current which will result in an exposure rate

in excess of 5 Roentgens (1.29 mC/kg) per minute at the point where the center of the useful beam enters

the patient unless the high level control is activated. Specials means of activation of high level control shall

be required. The high level control shall only be operable when continuous manual activation is provided

by the operator. A continuous signal audible to the fluoroscopist shall indicate that the high level control is

being employed.

4.9.4.1.2 Equipment without automatic exposure rate control. Fluoroscopic equipment which is not





4.9.4.1.2.2 When an optional high level control is activated. Special means of activation of high

level controls shall be required. The high level control shall only be operable when continuous manual

activation is provided by the operator. A continuous signal audible to the fluoroscopist shall indicate that

the high level control is being employed.

4.9.4.2 For equipment manufactured after May 19, 1995:

4.9.4.2.1 Equipment with automatic exposure rate control. Fluoroscopic equipment which is








the patient when the high level control is activated. Special means of activation of high level control shall



being employed.

4.9.4.2.2 Equipment without automatic exposure control. Fluoroscopic equipment which is not








the patient when the high level control is activated. Special means of activation of high level control shall



being employed.

4.9.4.3 Compliance with 4.9.4.1 and 4.9.4.2 shall be determined as follows:

4.9.4.3.1 If the source is below the x-ray table, the exposure rate shall be measured 1 centimeter

above the tabletop or cradle.

4.9.4.3.2 If the source is above the x-ray table, the exposure rate shall be measured at 30 centimeters

above the tabletop with the end of the beam-limiting device or spacer positioned as closely as possible to

the point of measurement.

4.9.4.3.3 In a C-arm type of fluoroscope, the exposure rate shall be measured 30 centimeters from

the input surface of the fluoroscopic imaging assembly.

4.9.4.3.4 For a variable SID C-arm type of fluoroscope the exposure rate shall be measured 30

centimeters from the input surface of the fluoroscopic imaging assembly, with the end of the beam-limiting

device or spacer positioned as close as possible to the point of measurement.

4.9.4.3.5 In a C-arm type of fluoroscope having an SID less than 45 centimeters, the exposure rate

shall be measured at the minimum SSD.

4.9.4.3.6 In a lateral type fluoroscope, the exposure rate shall be measured at a point 15 centimeters

from the centerline of the x-ray table and in the direction of the x-ray source with the end of the beam-

limiting device or spacer positioned as closely as possible to the point of measurement. If the tabletop is

movable, it shall be positioned as closely as possible to the lateral x-ray source, with the end of the beam-

limiting device or spacer no closer than 15 centimeters to the centerline of the x-ray table.

4.9.4.3.7 Periodic measurement of entrance exposure rate shall be performed for both maximum

and typical values in each mode used clinically annually, and after any maintenance of the system which

might affect the exposure rate. Results of the most recent measurements in each mode used clinically shall

be posted where any fluoroscopist may have ready access to such results while using the fluoroscope and

be included in the records required in RHB 4.2.16.1. The measurement results shall be stated in Roentgens

per minute and include the technique factors used in determining such results. The name of the person

performing the measurements and the date the measurements were performed shall be included in the

results.

4.9.4.3.8 Conditions of measurement of maximum entrance exposure rate are as follows:

4.9.4.3.8.1 The measurement shall be made under the conditions that satisfy the requirements of

RHB 4.9.4.3.

4.9.4.3.8.2 The kVp, mA, and other selectable parameters shall be adjusted to those settings

which give the maximum entrance exposure rate.

4.9.4.3.8.3 The x-ray system that incorporates automatic exposure rate control shall have

sufficient attenuative material placed in the useful beam to produce the maximum output of that system.

4.9.4.3.8.4 Testing shall be performed in each mode used clinically.

4.9.4.3.9 Conditions of measurement of typical entrance exposure rate are as follows:

4.9.4.3.9.1 The measurement shall be made under the conditions that satisfy the requirements of

RHB 4.9.4.3.

4.9.4.3.9.2 The kVp and mA shall be typical of clinical use of the x-ray system.

4.9.4.3.9.3 The x-ray system(s) that incorporates automatic exposure rate control shall have

sufficient attenuative material placed in the useful beam to produce a milliAmpere and/or kiloVoltage

typical of the use of the x-ray system.

4.9.4.3.9.4 Testing shall be performed in each mode used clinically.

4.9.5 Barrier Transmitted Radiation Rate Limits. The exposure rate due to transmission through the

primary protective barrier with the attenuation block in the useful beam, combined with radiation from the

image intensifier, shall not exceed 2 milliRoentgen (0.516 uC/kg) per hour at 10 centimeters from any

accessible surface of the fluoroscopic imaging assembly beyond the plane of the image receptor for each

Roentgen per minute of entrance exposure rate.

4.9.5.1 Measuring Compliance of Barrier Transmission.

4.9.5.1.1 The exposure rate due to transmission through the primary protective barrier combined

with radiation from the image intensifier shall be determined by measurements averaged over an area of

100 square centimeters with no linear dimension greater than 20 centimeters.

4.9.5.1.2 If the source is below the tabletop, the measurement shall be made with the input surface

of the fluoroscopic imaging assembly positioned 30 centimeters above the tabletop.

4.9.5.1.3 If the source is above the tabletop and the SID is variable, the measurement shall be made

with the end of the beam-limiting device or spacer as close to the tabletop as it can be placed, provided that

it shall not be closer than 30 centimeters.

4.9.5.1.4 Compression devices shall be removed from the useful beam during the measurement.

4.9.6 Indication of Potential and Current. During fluoroscopy and cinefluoroscopy the kV and mA shall

be continuously indicated.

4.9.7 Fluoroscopic Timer.

4.9.7.1 Means shall be provided to preset the cumulative on-time of the fluoroscopic x-ray tube. The

maximum cumulative time of the timing device shall not exceed 5 minutes without resetting.

4.9.7.2 A signal audible to the fluoroscopist shall indicate the completion of any preset cumulative on-

time. Such signal shall continue to sound while x-rays are produced until the timing device is reset.

4.9.8 Control of Scattered Radiation.

4.9.8.1 Fluoroscopic table designs when combined with procedures utilized shall be such that no

unprotected part of any staff or ancillary individual's body shall be exposed to unattenuated scattered

radiation which originates from under the table. The attenuation required shall be not less than 0.25

millimeter lead equivalent.

4.9.8.2 Equipment configuration when combined with procedures shall be such that no portion of any

staff or ancillary individual's body, except the extremities, shall be exposed to the unattenuated scattered

radiation emanating from above the tabletop unless that individual:

4.9.8.2.1 Is at least 120 centimeters from the center of the useful beam, or

4.9.8.2.2 The radiation has passed through not less than 0.25 millimeter lead equivalent material

including, but not limited to, drapes, Bucky-slot cover panel, or self-supporting curtains, in addition to any

lead equivalency provided by the protective apron referred to in RHB 4.2.9.2.

4.9.8.3 The Department may grant exemptions to RHB 4.9.8.2.2 where a sterile field will not permit

the use of the normal protective barriers. Automatic exemptions will be granted for fluoroscopic procedures

listed in Appendix E.

4.9.9 Spot-Filming Procedures. Fluoroscopic x-ray systems equipped with a spot-film device must

meet the following requirements for spot-film procedures:



In addition, it shall not be possible to make an exposure when the timer is set to a zero or off position if

either position is provided.

4.9.9.2 Timer Reproducibility. With a timer setting of 0.5 second or less, the average exposure period

( T ) shall be greater than or equal to 5 times the maximum exposure period (Tmax) minus the minimum

exposure period (Tmin) when 4 timer tests are performed: T ≥ 5 (Tmax - Tmin).

4.9.9.3 Exposure Reproducibility. The coefficient of variation of exposure shall not exceed 0.05 when

all selectable technique factors are held constant. This requirement shall be deemed to have been met if,



≥ 5 (Emax - Emin).

4.9.10 Mobile and Portable fluoroscopic x-ray systems which are used in a single location for a period

of greater than five consecutive days shall be considered a stationary fluoroscopic system, and shall meet

all the requirements of RHB 4.4.

4.9.11 Radiation Therapy Simulation Systems. Radiation therapy simulation systems shall be exempt

from all the requirements of 4.9.2, 4.9.4, 4.9.5, and 4.9.7 provided that:

4.9.11.1 Such systems are designed and used in such a manner that no individual other than the patient

is in the x-ray room during periods of time when the system is producing x-rays, unless the procedure

requires the presence of other individuals.

4.9.11.2 Systems which do not meet the requirements of RHB 4.9.7 are provided with a means of

indicating the cumulative time that an individual patient has been exposed to x-rays. Procedures shall

require in such cases that the timer be reset between examinations.

4.9.12 Fluoroscopic Quality Assurance. In addition to the requirements of RHB 4.2.16, the fluoroscopic

image resolution shall be tested as part of the quality assurance program. This shall be performed at least

annually.

4.9.13 Vertical Fluoroscopic Imaging Systems.

4.9.13.1 SSD. The SSD shall not be less than 38 centimeters.

4.9.13.2 Limitation of Useful Beam. All provisions of 4.9.2 apply.

4.9.13.3 Entrance Exposure Rates. All provisions of 4.9.4 apply.

4.9.13.4 Activation of the Fluoroscopic Tube. X-ray production in the fluoroscopic mode shall be



exposure(s) at any time, but means may be provided to permit completion of any single exposure of the

series in process.

4.9.13.5 Indication of Potential and Current. During fluoroscopy and cinefluorography the kV and

mA shall be continuously indicated.

4.9.13.6 Fluoroscopic Timer.

4.9.13.6.1 Means shall be provided to preset the cumulative on-time of the fluoroscopic x-ray tube.

The maximum cumulative time of the timing device shall not exceed 5 minutes without resetting.

4.9.13.6.2 A signal audible to the fluoroscopist shall indicate the completion of any preset

cumulative on-time. Such signal shall continue to sound while x-rays are produced until the timing device

is reset.

4.9.13.7 Operators shall remain in a protected area during exposures, or shall be protected by aprons

of not less than 0.25 mm lead equivalent material.

4.9.13.8 Spot-Filming Procedures. Fluoroscopic x-ray systems equipped with a spot-film device must

meet the following requirements for spot-film procedures:

4.9.13.8.1 Timers. Means shall be provided to terminate the exposure at a preset time interval,

preset product of current and time, a preset number of pulses, or a preset radiation exposure to the image

receptor. In addition, it shall not be possible to make an exposure when the timer is set to a zero or off

position if either position is provided.



minimum exposure period (Tmin) when 4 timer tests are performed: T ≥ 5(Tmax - Tmin).

4.9.13.8.3 Exposure Reproducibility. The coefficient of variation of exposure shall not exceed

0.05 when all technique factors are held constant. This requirement shall be deemed to have been met if,



≥ 5(Emax - Emin).

RHB 4.10 Bone Densitometry Systems. The requirements of this part apply to all stationary, portable, and

mobile x-ray bone densitometry systems.

4.10.1 Registration. All provisions of RHB 2.3 and 2.4 apply.

4.10.2 Shielding.

4.10.2.1 Stationary units. The registrant shall submit a shielding plan, as required by RHB 4.4 to the

Department for review and acceptance.

4.10.2.2 Peripheral units are exempt from 4.10.2.1.

4.10.3 Location. The bone densitometry system shall be placed in a controlled area. The operator,

ancillary personnel, and members of the general public shall be positioned at least one meter from the

patient and bone densitometry system during examination.

4.10.4 Administrative Requirements.

4.10.4.1 Personnel Monitoring. All provisions of RHB 3.12 and 3.22 apply.

4.10.4.2 Posting Requirements. All provisions of RHB 3.16.1, 4.2.7, and 10.2.1 apply.

4.10.4.3 Operators. All provisions of RHB 4.2.2 apply.

RHB 4.11 Computed Tomography (CT) X-ray Systems.

4.11.1 Equipment Requirements.

4.11.1.1 Tomographic Plane Indication and Alignment.

4.11.1.1.1 For any single tomogram system, means shall be provided to permit visual

determination of the tomographic plane or a reference plane offset from the tomographic plane.

4.11.1.1.2 For any multiple tomogram system, means shall be provided to permit visual

determination of the location of a reference plane. The reference plane can be offset from the location of

the tomographic planes.

4.11.1.1.3 If a device using a light source is used to satisfy 4.11.1.1.1 or 4.11.1.1.2, the light source

shall provide illumination levels sufficient to permit visual determination of the location of the tomographic

plane or reference plane under ambient light conditions.

4.11.1.2 Indication of CT Conditions of Operation. The CT x-ray system shall be designed to be used

during a scan or a scan sequence are indicated prior to the initiation of a scan or a scan sequence. On

equipment having all or some of these conditions of operation at fixed values, this requirement may be met

by permanent markings. Indication of CT conditions of operation shall be visible from any position from

which scan initiation is possible.

4.11.1.3 Initiation of Operation.

4.11.1.3.1 The x-ray control and gantry shall provide visual indication whenever x-rays are

produced and, if applicable, whether the shutter is open or closed.

4.11.1.3.2 Means shall be provided to require operator initiation of each individual scan or series

of scans.

4.11.1.3.3 All emergency buttons/switches shall be clearly labeled as to their functions.

4.11.1.4 Termination of Exposure.

4.11.1.4.1 Means shall be provided to terminate the x-ray exposure automatically by either de-

energizing the x-ray source or shuttering the x-ray beam in the event of equipment failure affecting data

collection. Such termination shall occur within an interval that limits the total scan time to no more than

110 percent of its preset value through the use of either a backup timer or devices which monitor equipment

function.

4.11.1.4.2 A visible signal shall indicate when the x-ray exposure has been terminated through the

means required by 4.11.1.4.1.

4.11.1.4.3 The operator shall be able to terminate the x-ray exposure at any time during a scan, or

series of scans under x-ray system control, of greater than 0.5 second duration. Termination of the x-ray

exposure shall necessitate resetting of the CT conditions of operation prior to initiation of another scan.

4.11.1.5 Extraneous Radiation. The system shall perform such that the radiation produced adjacent to

the tube housing assembly, including the tube port, during periods of time that scans are not being

performed does not exceed the levels permitted by RHB 4.3.3.

4.11.1.6 Additional Requirements Applicable to CT X-ray Systems Containing a Gantry

Manufactured After September 3, 1985.

4.11.1.6.1 The total error in the indicated location of the tomographic plane or reference plane

shall not exceed 5 millimeters.

4.11.1.6.2 If the x-ray production period is less than 0.5 second, the indication of x-ray production

shall be actuated for at least 0.5 second. Indicators at or near the gantry shall be discernable from any point

external to the patient opening where insertion of any part of the human body into the primary beam is

possible.

4.11.1.6.3 The deviation of indicated scan increment versus actual increment shall not exceed to

within 1 millimeter with any mass from 0 to 100 kilograms resting on the support device. The patient

support device shall be incremented from a typical starting position to the maximum incremented distance

or 30 centimeters, whichever is less, and then returned to the starting position. Measurement of actual versus

indicated scan increment can be taken anywhere along this travel.

4.11.2 Facility Design Requirements.

4.11.2.1 The control panel and x-ray control must be mounted in a permanently protected area outside

the computed tomography room. The operator is required to remain in that protected area during the entire

exposure.

4.11.2.2 Aural Communication. Provision shall be made for two-way aural communication between

the patient and the operator at the control panel.

4.11.2.3 Facilities designed with an open area in the control room that leads to the gantry shall mark

this open area conspicuously indicating not to stand or sit in this area during x-ray exposures.

4.11.2.4 Viewing Systems.

4.11.2.4.1 Windows, mirrors, closed-circuit television, or an equivalent shall be provided to permit

continuous observation of the patient during irradiation and shall be so located that the operator can observe

the patient from the control panel.

4.11.2.4.2 When the primary viewing system is by electronic means, an alternate viewing system

(which may be electronic) shall be available for use in the event of failure of the primary viewing system.

4.11.3 Dose Measurements and Spot Checks.

4.11.3.1 Dose Measurement.

4.11.3.1.1 Dose measurements of the radiation output of the CT x-ray system shall be performed

by, or under the direction of, a Class IX Vendor.

4.11.3.1.2 Dose measurements of a CT x-ray system shall be performed at intervals specified by a

Class IX Vendor and after any change or replacement of components which, in the opinion of the vendor

could cause a significant change in the radiation output.

4.11.3.1.3 Measurements of the radiation output of the CT x-ray system shall be performed with

a calibrated dosimetry system. The dosimetry system shall have been calibrated or intercompared with a

calibrated chamber within the preceding 2 years. The calibration of such system shall be traceable to a

national standard.

4.11.3.1.4 Records of equipment performance tests performed shall be maintained for inspection

by the Department.

4.11.3.2 Spot Checks.

4.11.3.2.1 Spot check procedures shall be developed by a Class IX vendor who specializes in

diagnostic radiological physics.

4.11.3.2.2 All spot checks shall be included in the calibration required by RHB 4.11.3.1, and

otherwise at time intervals and system conditions specified by a Class IX Vendor.

4.11.3.2.3 Spot checks shall include acquisition of images obtained with the phantoms using the

same processing mode and CT conditions of operation as are used to perform dose measurements required

by RHB 4.11.3.1. The images shall be retained, until a new dose measurement is performed, in one of two

forms as follows:

4.11.3.2.3.1 Photographic copies of the images obtained from the image display view; and

4.11.3.2.3.2 Images stored in digital form of the most recent spot check on a storage medium

compatible with the CT x-ray system.

4.11.4 Ancillary personnel who are not necessary for the safety of the patient shall not be present in the

area of the CT unit while exposures are being made.

4.11.5 CT units used in radiation therapy treatment planning are exempt from the requirements of RHB

4.11.3.1. All other provisions of RHB 4.11 apply.

RHB 4.12 Veterinary Radiographic Systems.

4.12.1 Administrative Requirements. All provisions of RHB 4.2 apply, except 4.2.2, 4.2.7, 4.2.10, and

4.2.11. No person other than a licensed practitioner or an adequately trained individual, as required by RHB

4.12.22, shall use equipment emitting ionizing radiation for diagnostic purposes.

4.12.2 Radiation Protection. All provisions of RHB 4.2.9 apply, except 4.2.9.3.

4.12.3 Holding of Patients and Films. All provisions of RHB 4.2.12 apply. In addition:

4.12.3.1 Each human holder in a veterinary facility shall utilize protective apparel.

4.12.3.2 Each veterinary facility that holds patients shall provide personnel monitoring devices. If the

human holder's hands are in or near the primary beam and lead gloves are not utilized, then ring badges

shall also be provided and worn.

4.12.4 General Requirements. All provisions of RHB 4.3 and 4.4 apply.

4.12.5 Means shall be provided for independent stepless adjustment of at least two dimensions of the x-

ray field.

4.12.6 Means shall be provided to indicate when the axis of the x-ray beam is perpendicular to the plane


4.12.7 Means shall be provided for visually defining the perimeter of the X-ray field. The total

misalignment of the edges of the visually defined field shall not exceed two percent (2%) of the distance


perpendicular to the axis of the x-ray beam.

4.12.8 The beam-limiting device shall indicate numerically the field size in the plane of the image

receptor to which it is adjusted.

4.12.9 Indication of field size dimensions and SID's used shall be specified in inches and/or centimeters

on the collimator. The indications on the collimator shall be such that aperture adjustments result in X-ray

field dimensions in the plane of the image receptor which correspond to those of the image receptor to

within two percent (2%) of the SID when the beam axis is perpendicular to the plane of the image receptor.

4.12.10 The beam-limiting device shall be provided with SID scales that reflect the actual SID(s) used

for radiographic procedures.

4.12.10.1 Means shall be provided to align the center of the x-ray field with the center of the image

receptor to within 2% of the SID.

4.12.10.2 Diaphragms or cones when provided for collimating the useful beam to the area of clinical

interest shall meet the requirements of RHB 4.7.2.

4.12.10.3 Minimum Field Size. The minimum field size at an SID of 100 cm shall be equal to or less

than 5 cm X 5 cm.

4.12.11 Radiation Exposure Control Devices.



In addition, it shall not be possible to make an exposure when the timer has been set to a zero or off position

if either position is provided.

4.12.11.2 X-ray Control.

4.12.11.2.1 An x-ray control shall be incorporated into each x-ray system such that an exposure can

be terminated by the operator at any time ("deadman" switch) except for exposures of one-half (1/2) second

or less, or during serial radiography when means shall be provided to permit completion of any single

exposure of the series in process.

4.12.11.2.2 The X-ray control shall provide visual indication observable at or from the operator

protected position whenever X-rays are produced. In addition, a signal audible to the operator shall indicate

that the exposure has terminated.



minimum exposure period (Tmin) when 4 timer test are performed: T ≥ 5 (Tmax - Tmin).

4.12.12 Exposure Reproducibility. The coefficient of variation of exposure shall not exceed 0.05 when

all technique factors are held constant. This requirement shall be deemed to have been met if, when four

exposures are made at identical technique factors, the value of the average exposure ( E ) is greater than or

equal to 5 times the maximum exposure (Emax) minus the minimum exposure (Emin): E ≥ 5 (Emax -

Emin).

4.12.13 Radiation from Capacitor Energy Storage Equipment in Standby Status. Radiation emitted

from the X-ray tube when the exposure switch or timer is not activated shall not exceed a rate of 2

milliRoentgen per hour at five (5) centimeters from any accessible surface of the diagnostic source

assembly, with the beam-limiting device fully open.


specified for that system by its manufacturer. In the absence of manufacturer's specifications, the deviation


4.12.15 Linearity. The following requirements apply when the equipment is operated on a power supply

as specified by the manufacturer for any fixed x-ray tube potential within the range of 40 percent to 100

percent of the maximum rated.

4.12.15.1 Equipment having independent selection of x-ray tube current (mA). The average ratios of

exposure to the indicated milliAmpere-seconds product (C/kg/mAs (or mR/mAs)) obtained at any tube

current settings shall not differ by more than 0.10 times their sum. This is: [X1-X2] < 0.10 (X1+X2); where

X1 and X2 are the average C/kg/mAs (or mR/mAs) values obtained at any two tube current settings.

4.12.15.2 Equipment having a combined x-ray tube current-exposure time product (mAs) selector, but

not a separate tube current (mA) selector. The average ratios of exposure to the indicated milliAmpere-

seconds product (C/kg/mAs (or mR/mAs)) obtained at any two mAs selector settings shall not differ by

more than 0.10 times their sum. This is: [X1-X2] < 0.10 (X1+X2); where X1 and X2 are the average

C/kg/mAs (or mR/mAs) values obtained at any two mAs selector settings.

4.12.15.3 Measuring compliance. Determination of compliance shall be based on 4 exposures, at each

of the two settings. These two settings may include any two focal spot sizes provided that neither focal spot

size is equal to or less than 0.45 millimeter, in which case the two settings shall be restricted to the same

focal spot size. For purposes of this requirement, focal spot size is the nominal focal spot size specified by

the x-ray tube manufacturer.

4.12.16 Light Localization.

4.12.16.1 When a light field is used to define the x-ray field, it shall provide an average illumination

of not less than 15 footcandles at 100 centimeters or at the maximum SID, whichever is less. The average

illumination shall be based upon measurements made in the approximate center of each quadrant of the

light field.

4.12.16.2 Exemptions to RHB 4.12.16.1 shall be granted if the registrant demonstrates to the

Department that their equipment is unable to meet these regulations.

4.12.17 SID Indication. Means shall be provided to indicate the SID. SIDs shall be indicated in inches

and/or centimeters, and shall be indicated to within 2 percent.

4.12.18 Fluoroscopic X-ray Systems. Veterinary fluoroscopic x-ray systems shall meet the following

requirements:

4.12.18.1 Limitation of Useful Beam.

4.12.18.1.1 Primary Barrier.

4.12.18.1.1.1 The fluoroscopic imaging assembly shall be provided with a primary protective

barrier which intercepts the entire cross section of the useful beam at any SID.

4.12.18.1.1.2 The x-ray tube used for fluoroscopy shall not produce x-rays unless the barrier is

in position to intercept the entire useful beam.

4.12.18.1.2 X-ray Field. The x-ray field produced by non-image intensified fluoroscopic equipment

shall not extend beyond the entire visible area of the image receptor. This requirement applies to field size

for both fluoroscopic procedures and spot filming procedures. In addition:

4.12.18.1.2.1 Means shall be provided for stepless adjustment of the field size;

4.12.18.1.2.2 The minimum field size at the greatest SID shall be equal to or less than 5

centimeters by 5 centimeters.

4.12.18.1.2.3 For image-intensified fluoroscopic equipment, neither the length nor the width of

the x-ray field in the plane of the image receptor shall exceed that of the visible area of the image receptor

by more than 3 percent of the SID. The sum of the excess length and the excess width shall be no greater

than 4 percent of the SID. In addition, means shall be provided to permit further limitation of the field.

4.12.18.2 Activation of the Fluoroscopic Tube. X-ray production in the fluoroscopic mode shall be



exposure(s) at any time, but means shall be provided to permit completion of any single exposure of the

series in process.

4.12.18.3 Barrier Transmitted Radiation Rate Limits.

4.12.18.3.1 The exposure rate due to transmission through the primary protective barrier with the

attenuation block in the useful beam, combined with radiation from the image intensifier, if provided, shall

not exceed 2 milliRoentgen (0.516 uC/kg) per hour at 10 centimeters from any accessible surface of the

fluoroscopic imaging assembly beyond the plane of the image receptor for each Roentgen per minute of

entrance exposure rate.

4.12.18.3.2 Measuring Compliance of Barrier Transmission.

4.12.18.3.2.1 The exposure rate due to transmission through the protective barrier with the

attenuation block in the useful beam, combined with radiation from the image intensifier shall be

determined by measurements averaged over an area of 100 square centimeters with no linear dimension

greater than 20 centimeters.

4.12.18.3.2.2 If the source is below the tabletop, the measurement shall be made with the input

surface of the fluoroscopic imaging assembly positioned 30 centimeters above the tabletop.

4.12.18.3.2.3 If the source is above the tabletop and the SID is variable, the measurement shall

be made with the end of the beam-limiting device or spacer as close to the tabletop as it can be placed,

provided that it shall not be closer than 30 centimeters.

4.12.18.4 Indication of Potential and Current. During fluoroscopy the kV and mA shall be continuously

indicated.

4.12.18.5 Mobile Fluoroscopes. In addition to the other requirements of this Part, mobile fluoroscopes

shall provide intensified imaging.

4.12.18.6 Control of Scattered Radiation.

4.12.18.6.1 Fluoroscopic table designs when combined with procedures utilized shall be such that

no unprotected part of any staff or ancillary individual's body shall be exposed to unattenuated scattered

radiation which originates from under the table. The attenuation required shall be not less than 0.25

millimeter lead equivalent.

4.12.18.6.2 Equipment configuration when combined with procedures shall be such that no portion

of any staff or ancillary individual's body, except the extremities, shall be exposed to unattenuated scattered

radiation emanating from above the tabletop unless that individual:

4.12.18.6.2.1 Is at least 120 centimeters from the center of the useful beam, or

4.12.18.6.2.2 The radiation has passed through not less than 0.25 millimeter lead equivalent

material including, but not limited to, drapes, Bucky-slot cover panel, or self-supporting curtains, in

addition to any lead equivalency provided by the protective apparel referred to in RHB 4.12.3.1.

4.12.19 X-ray Systems Designed for One Image Receptor Size. Radiographic equipment designed for

only one image receptor size at a fixed SID shall be provided with means to limit the field at the plane of

the image receptor, and to align the center of the x-ray field with the center of the image receptor to within

two percent (2%) of the SID, or shall be provided with means to both size and align the x-ray field such

that the x-ray field at the plane of the image receptor does not extend beyond any edge of the image receptor.

4.12.20 Veterinary Computed Tomography X-ray Systems - Where applicable, all provisions of RHB

4.11 apply.

4.12.21 Veterinary Dental Systems– Where applicable, all provisions of RHB 4.5 apply.

4.12.22 Operator Requirements. The registrant shall assure that all x-ray machines under his control

are operated only by individuals adequately instructed in safe operating procedures and competent in the

safe use of the equipment.

4.12.22.1 The registrant shall require persons operating registered equipment and associate equipment

and/or holding patients to receive, at a minimum, instruction in the following areas:

4.12.22.1.1 Radiation Protection. Training in radiation protection shall include, but is not limited

to, protective clothing; patient holding; time, distance, and shielding; radiation protection standards; and

the biological effects of radiation.

4.12.22.1.2 Darkroom Techniques/Digital Imaging Acquisition Systems. Training in darkroom

techniques shall include, but is not limited to, developing chemicals; film protection; cassettes; and screens.

Training in digital imaging acquisition systems shall follow protocol established by the manufacturer of the

digital imaging acquisition system.

4.12.22.1.3 Machine Safety. Training in machine safety shall include machine functions; safety

procedures; and recognizing problems.

4.12.22.1.4 General Operating Procedures. Training in general operating procedures shall include

patient positioning for x-ray exams; radiographic techniques; use of personnel monitoring devices; and

quality assurance procedures.

4.12.22.2 Instruction required by 4.12.22.1 shall begin within 30 days after employment. Training shall

be provided for each type of exam that the operator will be required to perform at that facility. The registrant

shall maintain a record of all training for each operator. Such records shall be made available for

Departmental inspection.

RHB 4.13 Medical Specimen Unit.

4.13.1 Administrative Requirements. All provisions of RHB 4.2.2.7 apply.

4.13.2 Radiation Protection. Upon installation, the medical specimen unit shall not be operated until a

physical radiation survey of the unit and areas adjacent to the unit has been performed. A radiation survey

of the unit and areas adjacent to the unit shall also be performed at least annually, and after any repair,

modification, or maintenance on the system. Documentation of the surveys shall be maintained for

inspection by the Department.

4.13.3 Tests of all safety devices such as interlocks shall be conducted annually for medical specimen

units. Documentation of such tests shall be maintained for inspection by the Department.

4.13.4 Radiation emitted from the medical specimen unit shall not exceed 0.5 milliRoentgens per hour

at an point five centimeters from the external surface.

4.13.5 When not in operation the medical specimen unit shall be secured.

USE OF X-RAY IN THE HEALTH PROFESSIONS RHB 4.2 General ... · 4.2.2.8 Dentists and their...

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